BATS
What do you call a little bat? A battle.
What do you call a bat in a belfry? A dingbat.
Why did the bat use mouthwash? Because he had bat breath!
Which bat knows the ABC’s? The alpha bat!
“Catch a bat in your hat and good luck will follow!” In Chinese art 5 bats represent the blessings of Health, long life, prosperity, love of virtue, and peaceful death. How we think about animals depends on our cultural biases.
Blind as a bat!
Wise as an Owl!
Smart as a fox!
Hungry as a bear!
Busy as a bee!
Bats are mammals and make up the order Chiroptera. There is evidence bats have existed for 50 million years or longer. They are warm blooded, nocturnal, nurse their babies with milk, and have fur. There are over 900 species of bats, but only 3 are vampires located in Central and South America. They suck blood from the wounds of birds and mammals. A lot of bats, including the flying fox, eat fruit. Other bats eat insects, frogs, fish, and other small animals. Because they are active at night their life seems mysterious.
Bats are the only mammals that can fly with “hand wings”. Their finger bones are elongated and connected with membranes. If we had fingers like a bat they would be longer than our legs! A few tropical bats have a wingspan of 6 feet, but most bats are small (1/10th of a pound in the U.S.). They have enlarged ears, bizarre noses, and the habit of hanging upside down. Their leaf- noses and large ears are involved in echolocation.
Bats produce a high- pitched burst of sound and then their brain analyses the echo for finding their way and finding their prey. Bats’ brains process the auditory information within those echoes as visual maps. All bats can see and all bats are sensitive to changing light levels because this is the main cue that they use to sense when it is nighttime and time to become active. To track down prey, avoid predators and find their way home in the dark, most bats depend on echolocation. They broadcast high-pitched sonar signals and listen for the echoes of sound waves bouncing off objects they’re looking for or obstacles in their path. Biologists listen to bat sounds with bat detectors that translate the ultrasonic signal into a range that we can hear. Bats increase the number of calls before they attack prey in order to pinpoint their meal. Many insects can hear echolocation and hide.
You may see bats at night around lights trying to catch insects. In the southwest, the long-nosed bats seek fruit nectar of the saguaro cactus and agave. The organ pipe cactus has flowers that open at night and is dependent on bats for pollination. Bats eat the fruits and disperse the seeds in their guano
Bats carry their babies for 4 months and have 1 single “pup” each year. The red bat has multiple births. Baby bats are born big like a 120 lb. woman having a 40 lb. baby. There are large maternity crèches but some species roost alone. Mother bats feed babies milk and babies make a distinct sound that the mother recognizes. Babies grow quickly and in 3 moths the little brown bat is ready to fly. The big brown bat is ready in 1 month. Fifty percent of babies die the first winter.
Bats are present throughout most of the world and perform vital ecological roles such as pollinating flowers and dispersing fruit seeds. Many tropical plant species depend entirely on bats to distribute their seeds. The greatest numbers of bats are in the tropics. Bats are absent from the poles and the very dry desert. Forty species live in the United States. Hawaii has 1 bat species. CA. has 25 bat species.
About seventy percent of bats are insectivores. Most of the rest are frugivores, or fruit eaters. A few species such as the Fish-eating bat feed from animals other than insects, with the vampire bats being the only mammalian parasite species. Bats play an important role in controlling pests (the mosquito.) They need to eat 30-50% of their body weight nightly. A single bat can eat enough mosquitoes in a single evening to save several people the agony of these insects that bite and cause great itching bumps protecting us from malaria, dengue, and yellow fever. Bat droppings are good fertilizer
Bats are disappearing due to the destruction of habitats, pesticides, and roosting sites being disturbed. Bats are very sensitive and susceptible to pesticides. The gray bat is endangered in the U.S., and so are the Hawaiian hoary bat, Indiana bat, Mexican long nosed, and big-eared bat.
Bats live 10 – 30 years and often migrate with the seasons to more sheltered sites. They may migrate 300 miles in all directions of their summer home. The free tailed bats may migrate 1000 miles to Brazil or Mexico. When bats hibernate, their body temperature drops to save energy and their heartbeat slows to 10 beats/minute. Their heart beats 13,000 times a minute in flight. Flight has enabled bats to become one of the most widely distributed groups of mammals. Apart from the Arctic, the Antarctic and a few isolated oceanic islands, bats exist all over the world. Bats are found in almost every habitat available on Earth. Different species select different habitats during different seasons — ranging from seacoast to mountains and even deserts — bat habitats have two basic requirements: roosts, where they spend the day or hibernate, and places for foraging. Bat roosts can be found in hollows, crevices, foliage, and even human-made structures; and include “tents” that bats construct by biting leaves.
Inside a cavern in Mexico there are 20 million bats hanging by their toes. It is the largest concentration of warm-blooded animals in the world! At dusk they all fly out to feed. Because they are active at night their life seems mysterious.
The scientists who discovered Onychonycteris finneyi, the oldest known bat fossil concluded that the prehistoric species could fly but that the sonar sense didn’t evolve until later. When scientists examined O. finneyi, as part of the study, their results suggested that the ancient species may have shared that same echo locating bone structure. Though echolocation is a relatively primitive trait, existing since at least 50 million years ago, researchers are still discovering new complexities about the sonar system.
Most bats do have bad eyesight, but they are definitely not blind. What they see can sometimes interfere with what they hear. We know that visual information can override echolocation information even when the echolocation information contradicts the visual information. A captive bat in a darkened room might fly into a window since it sees light coming through pane as an escape route, although echolocation sonar tells it there’s an obstacle in the way. In laboratory tests, bats have been shown to be able to distinguish shapes and colors. This is not unlike dolphins that use echolocation to hunt, especially in the murky depths. Their eyes, while small and sometimes poorly developed, are also completely functional, not to mention the fact that they have excellent hearing and sense of smell. Perhaps the saying should be changed to “Keen as a Bat”?
The smallest bat is the bumblebee bat (with a wingspan of 6 inches=15 cm. It is arguably the smallest extant species of mammal, with the Etruscan shrew being the other contender. The largest species of bat is the Giant Golden-crowned Flying-fox, which is 336–343 mm (13.23–13.50 in) long, has a wingspan of 1.5 m (4 ft 11 in) and weighs approximately 1.1–1.2 kg (2–3 lb).
Two traditionally recognized suborders of bats are:
- Megachiroptera (megabats)
- Microchiroptera (microbats/echolocating bats)
Not all megabats are larger than microbats. The major distinctions between the two suborders are: Microbats use echolocation: megabats do not with the exception of Rousettus and relatives. Microbats lack the claw at the second toe of the forelimb.
The ears of microbats do not close to form a ring: the edges are separated from each other at the base of the ear. Microbats lack under fur: they are either naked or have guard hairs.